Process of making tap-hole plugs.



No. 718,828. PATENTED JAN. 20, 1903.

F d A A I 1 swam M Jlndrew .DiG/ggy NlTED TATES PATENT OFFICE.

ANDREWV DIGKEY, OF NIAGARA FALLS, NEWV YORK.

PROCESS OF MAKING TAP-HOLE PLUGS.

SPECIFICATION formingpart of Letters Patent No. 718,828, dated January20, 1903.

Original application filed December 2,1901, $erial1lo. 84,448. Dividedand this application filed October 31, 1902. Serial No.129,604. (Nospecimens.)

To all whom, it may concern:

Be it known that I, ANDREW. DIcKEY, a citizen of the United States,residing at Niagara Falls, in the county of Niagara and State of NewYork, have invented certain new and useful Improvementsin Processes ofMaking Tap-Hole Plugs; and I do hereby declare the following to be afull, clear, and exact description of the invention, such as will enableothers skilled in theart to which it appertains to make and use thesame.

My invention relates to new and useful improvements in the process ofmakingtap-hole plugs as applied to a means for reducing or meltingmetals, by the use of which the metal may be retained or Withdrawn fromits container, as desired, without oxidation or contamination withforeign ingredients to an injurious degree or breaking of lining to tapthe same; and which apparatus consists, essentially, of a reducing ormelting pot lined with a material especially adapted to preventcontamination. of the metal contained therein-such, for instance, ascarbon-having an outlet from the lower part thereof, provided with aremovable plug or closure of reconstructed oxyhydrocarbon or cellularmaterial such as might be produced by forming the same of paper orsimilar manufactured substance capable of being transformed into carbonor friable charcoal by the application of heat in juxtaposition thereto,this being a division from my application Serial No. 84,448, filedDecember 2, 1901.

By way of illustrating myinvention and the manner in which the sameisperformed reference may be had to the accompanying drawings, of'whichFigure 1 is a vertical longitudinal section of a reduction-pot providedwith my improved tap-hole plug. Fig. 2 is an enlarged view of a green orunfinished plug composed of a materialsuch as compressed paper-pulp,sawdust, or other reconstructed or reassociated oxyhydrocarbonoapable ofbeing transformed by the action of heat and exclusion of air into myimproved tap-hole plug, as hereinafter set forth. Fig. 3 is an enlargedview of my improved tap-hole plug, clearly illustrating the componentparts thereof. Fig. 4 is a view of a section of reduction-pot, showingmy tap-hole plug inserted in the tap-hole thereof, the carbon bextending into the molten metal contained therein. 'Fig. 5 is a similarView showing inserted in the tap hole thereof a shorter plug having itsouter end protected from contact with the atmosphere, and consequentignition when heated, by a coating of impervious substance 0.

Referring to the illustrations, the letter A designates a metallic potor receptacle; B, the carbon lining of a reduction-pot; O, the moltenbath therein containing metal; D, the tap-hole thereof; E, a green orunfinished plug for making my tap-hole plug, or, as shown in Fig. 3,constitutes a part of the finished plug; F, a metal-outlet spout, and Ga reinforcingflange of the same.

Similar letters of reference illustrate corresponding parts in thevarious views.

My invention has particular reference to the process of making tap-holeplugs to be used in the reduction or melting of such metals asaluminium, which are prone to become contaminated with foreignsubstances, which render them practically valueless for many commercialpurposes; but it is not limited thereto, as it maybe employed for manyother metals.

Heretofore in the reduction of aluminium by fusion and electrolysis.serious difficulty has arisen in removing the reduced or molten metal.from the pot or container in which it is retained, the usual methodbeing to uncover the molten contents and ladle or dip the same out,which method, it can be readily seen, involves greatloss, because themetal becomes oxidized and the bath cooled and chilled during theprocess of Withdrawal. Up to the time of my originalinvention, which iscovered by United States Letters Patent No. 602,575, dated April 19,1898, it was considered impossible to provide a melting or reduction pothaving a tap-hole or Vent for drawing off the metal, for the reason thatit had been found impossible to plug the same by any known means,because the intense heat would not permit the use of a metal plug or theuse of clay, porcelain, or similar substances without contamiuating thealuminium with the metal of the plug or some of the ingredients of theclay, such as silicon, to an injurious degree and the formation of denseand vitreous compositions, which could only be tapped by drillingtherethrough and breaking linings, thus occasioning great loss andexpense. In myprevious patent cited I overcame this difficulty by theuse of a wooden or charcoal plug. I have found, however, thatreconstructed wood, cellulose, or similar oxyhydrocarbon may beeffectively employed to advantage instead of the wooden or charcoalplugs, as previously claimed.

The object of my invention, therefore, is to make a tap-hole plug to beemployed in combination with a melting-pot lined with carbon or similarmaterial having an outlet from the lower part thereof, a removable plugor stopper composed of reconstructed or reassociated oxyhydrocarbon,such as cellulose, which is capable of being transformed into carbon orfriable charcoal when heated, the principal advantage being that I canemploy these plugs or stoppers made of compressed sawdust, paper-pulp,orsimilar material with or without a binding constituent of glutinous orsimilar character, which plug or stopper may be made from the refuse ofwood-work ing establishments at a less cost than from wood direct, thesaid removable plug when adjusted in the melting-pot or container beingexcluded when in use at the part heated to igniting temperature from theatmosphere by an impervious or air-excluding material which will preventthe same from oxidizing or burning.

In the preparation of a reducing or melting pot and closure-plug of thecharacter described I proceed as follows: First, I provide a pot orreceptacle A, preferably of iron, adapted to be lined with carbon orcarbonaceous material B. I then prepare a material for carbon lining Bby taking ground carbon or coke, heating the same, and mixing it. with aportion of fine quality of tar to a consistency of mortar-t. 6., tarenough to act merely as a binder when baked. I then put a quantity ofthis mixture of tar and ground carbon in the iron receptacle A and tampthe same solidly on the bottom thereof. I then place upon this solidcarbon base the mold or form of wood or other material, of such size andshape as I desire to make the interior of the meltingpot, andcommunicating therewith a tap-hole mold, preferably of conical ortapering form, extending in adownward direction through an opening ororifice d in the lower side of the iron receptacle A. I then fill thespace between the mold or form and the iron receptacleA with a mixtureof tar and ground carbon, as before stated, preferably introducing asmall quantity at a time and tamping the same until it becomes solid andcom pact and carefully filling the same around the tap-hole mold, sothat when the same is withdrawn it will leave a tapering tap-hole D. Iprefer in the formation of this tap-hole D to employ a piece of woodofdesired form. When the same is thoroughly filled and tamped with thecarbon mixture, the whole pot is then placed in an oven or furnace,where it is thoroughly baked until the carbon assumes a solid compactform and most of the volatile carbonaceous material has been dissipated.During the baking of this carbon lining the wooden plugs and molds areburned up or converted into charcoal. After the pot has been thoroughlybaked, which usually takes about twelve hours, it is allowed to coolgradually, removed from the furnace, cleaned out, and it is ready foruse.

In preparing a plug for the tap-hole I prefer to take a segregatedcarbohydrate or cellulose, such as wood-sawdust or paper-pulp, or amaterial made from the same, such as paper, and either compress the samewith suitable binder, such as paste or size, in sufficient quantity, or,if paper material is employed, to wrap the same in layers, the wholeobject being to produce a plug of carbonaceous material, as shown at E,Fig. 2, preferably of the carbohydrates, such as cellulose, which willwhen heated on exclusion of air be converted into a porous friablecharcoal, as shown at b, Fig. 3, and which when produced in the tap-holeof the pot when employed during process of reduction prevents the metalfrom escaping or becoming contaminated and may be easily removed withoutinjuring the lining of the pot when it is desired to tap the same. Ifind that by employing this form of plug, as shown at E, Fig. 2,consisting of reconstructed carbohydrates or cellular matter capable ofbeing transformed when heated into charcoal, I can accomplish the resultdesired, as before described, more cheaply and in a more economical andsatisfactory manner than can be accomplished by the use of wood alone,which necessarily causes considerable waste of material in its shapingand formation. After forming this preparatory or green plug, so tospeak, of oxyhydrocarbon I place it in the tap-hole D of amelting orreduction pot, as shown in Fig. 1, introduce a fusible material into thepot and fuse it, preferably by electric heat, whereupon the heatcommunicated to the inner end of the green plug E in the tap-hole Dconverts it in an outward direction into carbon or charcoal, as shown atb, Fig. 3, followed by asection of intermediate educts of destructivedistillation of the constituents of the green or unfinished plug a andbacked by the undecomposed portion of the green plug E, which being sucha distance from the source of heat remains practically unchanged in along plug, thus constituting one of the component parts of the finishedplug as shown complete in Fig. 3 and acts as a medium for preventing theheated educts orintermediate compounds of destructive distillation frombecoming ignited by excluding the air therefrom, so the same is notconsumed by combustion. Should the green or unfinished plug introducedin the tap-hole D be so short that the heat communicated from themelting pot would transform it into carbon and intermediate educts ofdestructive distillation, then I prefer to prevent it from igniting inits heated condition by application to it of a substance c, Fig. 5, suchas clay, which will exclude the-atmosphere therefrom.

It can be seen from the foregoing description that my invention consistsspecifically in the making, in combination with a meltingpot, of a taphole plug composed of carbon, intermediate educts of destructivedistillation of oxyhydrocarbons, and asubstance capable of excluding theatmosphere from contact with the portion of the plug heated to anigniting degree while inserted in the tap-hole D and preferably producedfrom reconstructed carbohydrates, cellular matter, or other carbonaceousmaterial of like character capable of being converted into charcoal whenheated out of contact with oxygen, the portion of the plug heated to anigniting or carbonizing degree being excluded from the atmosphere by amaterial which prevents the transmission or passage through of oxygen insufficient quantity to consume the same. This may be either by theexcess of carbohydrate or material of which the plug is composed incases Where it is of sufficient length E, Fig.3,or by the application toor coating of the exterior of said plug with a foreign substance ormaterial capable of accomplishing the same result, as shown at c, Fig.5, which may be considered as a part of the plug itself and theequivalent of the unchanged portion E, Fig. 3.

In the continuous operation of a reductionpot when enough metal has beenreduced by electrical or other means the tap-hole plug is readilyremoved by withdrawing the same from the tap-hole and the metalwithdrawn, after which another green plug is inserted, stopping the flowof fluxes, &c., and that by action of heat communicated at the inner endthereof in its position in the tap-hole being excluded from theatmosphere is converted into my improved tap-hole plug, as beforedescribed and as illustrated in Fig. 8.

This composite tap-hole plug may be first made by heating in asuitablemold and thereafter inserted in the tap-hole of a melting or reductionpot; but I have found it advisable and preferable to produce it directlyfrom a green plug within the tap-hole, as herein set forth.

It may be noted that in the making and employment of my improvedtap-hole plug I start with a more dense and compact material than theresultant product, and the process of conversion from a dense to afriable nature, which admits of its being readily withdrawn when it isdesired to tap or draw 0d the contents of the melting or reducing pot,constitutes an important feature of my invention, as in other cases itis found that the resultant product of the plugging medium is of moredense and vitreous nature than the original material employed, whichoccasions considerable loss when tapping, because it becomes necessaryto forcibly drill out or through the same, thereby breaking anddestroying the lining of the reducing or melting pot to a large andinjurious degree.

The term carbon as employed throughout this specification and claims hasreference to carbon-such as charcoal, coke, &c. containing suchcontamination as small portions of alumina, potash, soda, 850., commonlyknown as ash, as well as pure carbon per se, and the terms reconstructedand reassociated with reference to oxyhydrocarbons, such as cellulose,are intended to imply a compact body or substance composed ormanufactured of pieces or particles of said material united in mass andthe term oxyhydrocarbon to a more or less dense composition, such ascompressed sawdust or similar carbohydrate, capable of transformationinto a porous or less dense substance, such as charcoal or material ofanalogous nature, by action of heat and exclusion of air. The termeduct, employed herein, is intended to imply the residual compound orsubstance left after separation wholly or in part of the volatileproducts generated by the action of heat on the raw material employed.

The following predominating features and distinctions of my improvedtap-hole plug may be noted: First, the composition of which the greenplug is composed being reassociated or reconstructed oxyhydrocarbon-suchas sawdust, with or without additional binder of glue, size, or similarmaterialis such a bad conductor of heat that it is not readilytransformed or decomposed by the action of heat, as wood, so that ashorter plug may be used without being wholly converted into charcoal;second, the finished plug being only partly converted into charcoal andhaving an exterior or adjoining portion of the more dense intermediateeducts of destructive dis-,

tillation assists in maintaining the composition of the plug in thetap-hole against the weight or pressure of the molten materials in themelting pot or furnace, which plug would be more readily forced out ifit consisted wholly of pure charcoal; third, the employment of a greenplug of compressed sawdust,with or without a binder, produces whenheated a tap-hole plug of such cohesive character that it can be readilywholly withdrawn intact when desired with one operation instead ofhaving to be picked out in fragments, as is the case with pure charcoal,and thereby efiecting a saving of time and more perfect operationwithout injuring the tap-hole or contaminating the withdrawn metal withparticles of fine carbon; fourth, the finished plug consists of portionsof sections of varying densityviz., the soft carbon or charcoal tip, themore dense intermediate educts of destructive distillation, and thestill more dense exterior uncovered portion capable of excluding airfrom the portion which becomes heated to igniting temperaturewherebydestruction by combustion is prevented, which con sistehce of sectionsof varying density renders it especially adaptable for a tap-hole plugi1for the reasons hereinbefore fully set fort I do not desire to confinemyself to the exact process set forth herein for producing my improvedtap-hole plug, but reserve all rights to produce the same by simplemechanical construction or preparation either during or prior toutilization in a reducing or melting furnace, my invention consisting,essentially, in the process of makinga new and novel taphole plug ofcomposite construction, as hereinbefore clearly set forth.

Having now described my-invention, what I claim as new, and desire tosecure by Letters Patent, is-- l. The process of making a compositetaphole plug of soft or friable nature which con sists in exposing oneend of a dense or compact carbonaceous body to the action of heat whileexcluding air from said end and in continuing the heating until the endof the body is carbonized and the adjoining portion of the body hassuffered partial destructive distillation.

2. The process of making a composite taphole plug of soft or friablenature which consists in exposing one end of a dense or compact cellularbody to the action of heat while excluding air from said end andcontinuing the heating until the end of the body is carbonized and theadjoining portion of the body has suffered partial destructivedistillation.

3. The process of making a composite taphole plug of soft or friablenature which consists in exposing one end of a dense or compact bodyconsisting of a reassociated oxyhydrocarbon to the action of heat whileexcluding the air from the said end and in continuing the heating untilthe end of the body is carbonized and the adjoining portion of the bodyhas suffered partial destructive distillation.

4. The process ofmaking a composite tap hole plug which consists inexposing one end of a plug containing a carbohydrate to the action ofheat while excluding air from said end and continuing the heating untilthe end of the plug is carbonized and the adjoining portion of the plughas suifered partial destructive distillation.

5. The process of making a tap-hole plug which consists in inserting aplug containing cellulose in the tap-hole of a reducing or meltingfurnace and then exposing it to the action of heat sufficient to convertit partly, in an outward direction, into carbon and intermediate eductsof destructive distillation.

In testimony whereof I aflix my signature in presence of two witnesses.

ANDREW DIOKEY.

Witnesses:

S. M. OWEN, C. C. WRIGHT.

